1. Field of the Invention
The present invention relates to an apparatus and method identifying a disc type in a disc drive, and more particularly, to an apparatus and method of identifying a type of a disc using an LPP (Land Pre-Pit) formed on the disc.
2. Description of the Related Art
There are various types of recordable discs, such as a recordable CD (compact disc) and a recordable DVD (digital versatile disc). The recordable DVDs can be divided into DVD−R/+R type discs, i.e., one-time recordable discs, and DVD−RW/DVD+RW type discs, i.e., re-recordable discs on which data can be recorded several times.
Although the shapes of the above-mentioned discs are the same regardless of the types of the discs, their physical disc formats are different according to the types of the discs. That is, the recordable discs use periodic wobble grooves and utilize them to produce clock signals in a recording mode. The reason for wobbling the grooves is that the recordable discs cannot produce clock signals from reproduction signals. Accordingly, in the case of the recordable discs, tracking and rotation speed of the disc are controlled using wobble signals in a recording mode.
The recordable discs have different wobble frequencies and amplitudes according to the types of the discs. Further, methods of forming wobble grooves are different according to the types of recordable discs. Particularly, in the case of DVD−R/−RW type discs, position information of a groove track is recorded by forming a pre-pit in a land track on which data is not recorded. The pre-pit formed in the land track is called LPP (Land Pre-Pit). The LPP is recordable in wobble shapes, and used to store an absolute address of the portion where data is not recorded, i.e., a block address number, and other information. However, in case of DVD+R/+RW type discs, the wobble is formed in a phase modulation method.
In order to drive various types of discs having different physical formats in the same disc drive, the disc drive must be able to set operational conditions adequate to the physical format of a disc to be driven during a lead-in time period for the disc. The setting of the operational conditions is for normally reading data from or writing data to the disc. Setting a servo gain to stabilize servo operations is an example of setting the operational conditions of the disc drive. In order to set the operational conditions, the type of the disc to be driven must be correctly identified.
In a conventional method of identifying a type of a disc, the disc type is identified on the basis of an ID (identification) code recorded in a lead-in area of the disc. That is, after the operational conditions of a disc drive are set to read the ID code, the disc type is identified using the ID code recorded in the lead-in area and the currently set operational conditions are adequate for the identified disc type, the lead-in operation for the disc is over.
However, if the operational conditions of the disc drive are not adequate for the identified disc type, the disc drive must retry the setting of the operational conditions adequately for the identified disc type. Accordingly, in the case where the operational conditions of the disc drive are not adequate for the identified disc type, the lead-in operation is inefficiently performed.